Antibiotics, often the same or nearly identical to those used in humans, are wodely used in raising food animals. Antibiotics are especially relied upon by gigantic factory farms, where thousands of pigs, cattle or poultry are often crammed tightly together with little or no access to fresh air and pasture. Low levels of antibiotic are fed to these animals, not to treat sickness but to spur them to market weight more quickly, and to "prevent" infections in animals stressed by the crowded conditions. Factory farms also dump millions of pounds of untreated manure into the environment each year, manure likely containing antibiotics. This practice helps breed bacteria resistant to these drugs.

Most meat produced in the U.S. today is raised under these crowded factory farm conditions. The latest and most transparent estimates are that at least 8 times more antibiotic are given each year to healthy cows, pigs and birds than are used to treat all the sick people in this country. Public health authorities, like the Centers for Disease Control and Prevention (CDC), now link low level antibiotic use in food animals to meat contaminated with bacteria resistant to these drugs. Rising numbers of people are becoming infected with these resistant bacteria, and are harder to treat because they respond poorly or not at all to these compromised medicines.

Responsible producers and retailers now provide meat from animals raised without the use of antibiotics. A growing body of evidence suggests that these meats are less likely to be tainted with antibiotic-resistant bacteria. Resistant bacteria can be transmitted through food and are sickening rising numbers of people with infections that are more difficult or impossible to treat with these antibiotics.